The present invention relates to a radiation shielding body used for protecting a worker or workers in radiation environments from radiation exposure.
In a case where any work is carried out in radiation environments, a radiation shielding body is used as a means for protecting a worker attending to the work.
An example of the radiation shielding body is proposed in Japanese Utility-model Laid-open Application 61-147998. The proposed radiation shielding body has a bag of synthetic resin, which has a radiation shielding liquid such as water, sodium borate, etc. injected therein and is arranged to cover piping having therein radioactive substances, and shields radiation with the radiation shielding liquid. In this proposed example, a plurality of the bags are connected to each other by fasteners at the outer periphery of the piping containing therein radioactive substances, and the connected bags are wound around the outer periphery of the piping and used. Therefore, the piping supports the plurality of bags and the radiation shielding liquid.
In radiation shielding work that winds a radiation shielding body around piping and devices having therein radioactive substances and covers them therewith, since a worker attending to the work must approach the piping and devices, the worker is in danger of being exposed to radiation.
In a case where the piping and devices are covered with thermal insulating material, since work for removing the thermal insulating material is carried out before winding the radiation shielding body around the piping and devices, a worker attending to the removal of the thermal insulating material also is in danger because the dose of radiation to which the worker is exposed increases.
In a case where the method of winding the radiation insulating body around the piping and devices and covering them with the radiation insulating body is taken, when the piping and devices have complicated shapes as in piping provided with pipe rests and valves thereon or elbow portions and T-shaped branch portions of piping, it is difficult and takes much working time to wind the radiation shielding body around that portion, whereby there occurs a danger that the radiation exposure dose to a worker attending to the work for winding the radiation shielding body around that portion increases.
Further, a radiation shielding body that a radiation shielding liquid such as water is enclosed inside a container made of resin or metal is known in JP A 59-12398, JP A 8-211192, JP A 6-230178.
In those prior arts, since the container containing therein liquid such as water as a radiation shielding liquid stands upright by itself and is arranged on a floor, it is difficult to set it on a portion made narrow by obstacles disposed on the floor.
Further, since the container has water inside, it is difficult to make the height tall and shield radiation in a vertically wide region by one container.
In order to increase a vertical region covered by one radiation shielding body and make it possible to use it for radiation shielding in a narrow portion, a radiation shielding body, which is made of a lead plate or lead hair worked in a thin and wide mat-like shape and which is hung for use or stood between radioactive devices and a worker, is disclosed in JP A 7-84091.
However, the radiation shielding body formed of the lead plate or lead hair worked in a mat-like shape has a much heavier specific weight than radiation shielding liquid, and when radiation shielding is effected over a wide range, its weight becomes larger and its handling such as mounting, removing and transferring it is not easy. Therefore, there occurs a danger that the worker attending to the work could receive a large dose of radiation exposure during the handling of the radiation shielding body in a radiation environment.